class·mate (kl?s?m?t?)n. A member of the same class at school.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.classmate (?kl??s?me?t) n (Education) a friend or contemporary of the same class in a school, college, etcCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014class?mate (?klæs?me?t, ?kl?s-) n. a member of the same class at a school or college. [1705?15, Amer.] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.